Brakes: Re-set brake fault valve & switch on 2 circuit 121

[Charlie69Amazon]

Hi all,

My brake light is on after bleeding the brakes without removing the switch. My mistake as I have learned from the research I have done. A question on how to move the shuttle valve back to center position: Can I move it by bleeding one of the caliper or wheel cylinder bleed nipples on the other circuit? I will do this with the switch removed of course. However I don't know how will I know it has centered, and not moved across to isolate the circuit being bled?

The position of the shuttle valve block with switch is awkward with the switch facing down. It is not possible to see the positon of th eshuttle valve wihtout a borescope. I am tempted to install it upside down with the switch on top so I can see the shuttle valve and see if it is centered. Has anybody done this? Can you see any problems with installing it this way?

Thanks,
Chalrie Perry 69 121 B20 with dual circuit brakes